Today I implemented AdSense onto the site of the company that I work for, and I decided to try using the "image" option for it. Unlike my many personally-run sites, the company site avails itself to mostly 120 by 600 ads. And, from what I've found so far, they have good image ads that go with it... Everything from politics to ketchup to a new show on Fox TV.
Of course, it's not possible to track the success of the image ads at this point (versus the regular AdSense ads), but for those of you who have used the image ads, have you experienced good results?